Printed cable connector



Sept. 22, 1964 H. G. MARTINECK 3,149,897

PRINTED CABLE CONNECTOR Filed Aug. 29, 1961 2 Sheets-Sheet 1 HANS G.MARTINECK INVENTOR.

FIG. 6 BY A T TORNE YS Sept- 2 1964 H. G- MARTINECK PRINTED CABLECONNECTOR Filed Aug. 29, 1961 2 Sheets-Sheet 2 ATTORNEYS United StatesPatent 3,149,$97 PRKNTED CABLE CONNECTGR Hans G. Martinech, Huntsville,Ala, assignor to the United States of America as represented by theAdministrator of the National Aeronautics and Space Administration FiledAug. 29, 1961., Ser. No. 134,782 2 Ciaims. (Cl. 339-176) (Granted underTitle .35, US. Code {1952), see. 266) The invention described herein maybe manufactured and used by or for the Government of the United Statesof America for governmental purposes without the payment of anyroyalties thereon or therefor.

This invention relates generally to electrical connectors.

More specifically, the invention relates to a connector for electricallyconnecting printed cable to printed cable .or printed cable to printedboard.

Since the advent of the printed cable and printed circuit, that is, acable or circuit printed on or imbedded in an insulation material, .apressing need has arisen for an electrically and mechanically reliableconnecting. means which is relatively light in weight, strong, durable,and resistive to shock and vibration, yet which is simple to manufactureand use. Much time, money, and effort have been expended in endeavoringto perfect such devices, but until the present invention, no trulysatisfactory device has been developed.

The devices of the prior art have, in general, been subject todisadvantages which materially limited their usefulness and efficiency.One such deficiency was a liability to deformation .on insertion of aplug within the connector, since the plug pushing down on one side orend of the clip contacts resulted in a corresponding raising of the clipcontacts on the other end, with the result that when a second plug wasinserted in the opposite end the clip contact would be permanentlydeformed. 'In addition, the electrical contact elements of many of theprior art devices were subject to sliding or displacement in thelongitudinal direction when the plug was forced into the connector. Thetolerances which were required between the elements of the prior artwere also, on the whole, relatively quite small so that precision inmanufacture was a prerequisite, adding greatly to the manufacturingcosts. Moreover, in the known devices of the prior art, the contactelements of the connector member had a relatively great deflection inrelation to their length, thereby creating a non-uniform contactpressure and contact resistance and when too stiff a consequentlygreater amount of wear on both the plug and connector.

Other disadvantages inherent in the known prior components includeddifficulty in mounting the plug on an associated electrical componenthousing and the inability of such prior art connectors to retain theplugs when subjected to vibrations, dynamic loads or inadvertentdisconnecting forces. These failings were of particular disadvantage inthe application of such circuitry to space vehicles.

It is a general object of this invention to provide an electrically andmechanically reliable connector for employment with printed cables andcircuits.

It is a further general object of the invention to provide anelectrically reliable connecting device which is resistive to shock andvibration.

It is a further object to provide such a device which is simple tomanufacture and use.

It is a more specific object of this invention to provide a connectorfor a printed conductor cable in which the elements thereof are notsubject to deformation upon the application of the cable plug.

It is an additional object of this invention to provide such a connectorwherein the contact elements are'not subject to being displaced on theapplication of a plug, and wherein the contact elements are preloaded.

According to the present invention, the above and other objects areachieved by providing a body member having .an elongated rectangularopening therein, the body member retaining curved spring contactelements for electrical contact with conductors in an associated plug,which spring contact elements are provided with hooked ends and aninternal foot mating or interfitt-ing with the internal configuration ofthe connector housing whereby the contacts resist deformation anddisplacement on insertion of plug members.

In addition, the connector housing is provided with plug retaining meanspreventing accidental displacement of the plug on the application ofdynamic loads, plug positioning means preventing improper insertion .ofthe plug and thereby avoiding short circuits, dust seals, andincorporates a means for mounting the connector to the surface ofanother element.

Referring now to the drawings, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in FIGURE 1 an exploded isometric View of the device ofthe invention and the associated plug;

FlGURE 2 is a sectional View of the associated plug element fororientation;

FIGURE 3 is a plan view of the connector and associated plug of thisinvention;

FIGURE 4 is a sectional view of the device of the invention taken alongthe line IV-IV of FIGURE 3;

FIGURE 5 is a rear view, with the dust cover removed, of the connector;

FIGURE 6 is a side elevational View of the spring contact element; and

FIGURE 7 is a cross-sectional view of the contact element taken on theline VIIVII of FIGURE 6.

Referring first to FIGURES 1 and 4 for purposes of orientation only,there is shown a flat cable 145 having electrical conductor elements 150therein which cable has secured at one end of a modifiedplug element149, basically the same as, and more fully disclosed in applicationSerial No. 169,789, filed May 12, 1961, by Wilhelm Angele and Hans G.Martineck. This plug is adapted to be inserted into the connector 19 asmost clearly shown in FIGURE 4 and more specifically set forthhereinafter.

Having reference now specifically to FIGURE 2 Wherein the plug is shownin detail, it is seen that this plug in general comprises a T-shapedbody 142 having 'a ridge portion 143 and an insert portion 144 formed onthe terminal portion of the flat electrical cable 145. The electricalcontact surfaces 146 and 147 of the plug are formed by the outermostsurfaces of the raised offset port-ion-s 148 and depressed offsetportions 14$, respectively, of the flat conductors 159 imbedded in thecable 14-5. The ridge portion 143 of the T-shaped body 142 encircles andconfines the cable adjacent one side 151 of the offset portions 148 and149 at the end of the cable 145, and the insert portion 144 confines thecable between the ridge portion 143 and terminus 152 whereby theelectrical contact surfaces 146 and 147 are adjacent or flush with theupper surface 153 and lower surface 154, respectively, of the insertportion 144. The raised offset portions 148 and lowered offset portions149 are alternated between adjacent conductors, whereby current leakagebetween the electrical contact surfaces 146 or 147 is held to a minimum.

The ridge portion 143 of the plug 142 serves as astop which limits theextent of insertion of the insert portion 144 into the receiving matingreceptacle or connector 10,

3 as more fully described hereinafter, and also serves as a means bywhich the plug 142 may be manually grasped. The insert portion 144 ofthe plug 142 is provided with polarizing keys 155 and 156 (as best seenin FIGURE 1), located respectively on the upper left side and upperright side of the plug insert portion 144. The operation of thepolarizing keys 155 and 156 will be described more fully hereinafter inconjunction with the connector element 10.

In addition, the plug element 1413 is provided on the T-shaped body 142with lugs 141 (as best seen in FIG- URE 1), these lugs 141 beingdisposed one on each end of the ridge portions 143 for cooperation witha locking means 51 formed on the body of the connector 19, as more fullyexplained below.

As seen with reference to FIGURES l and 35 and, with particularreference to FIGURE 3, the connector element of this invention comprisesa substantially rectangularly shaped device, indicated generally by thenumeral 10, which is formed by substantially U-shaped top and bottomelements 11 and 12, respectively (see FIG- URE secured together byrivets 13 or their equivalent, which securing means pass through andbear against a mounting flange 14 as shown in FIGURE 3. This mountingflange 14 extends around the connector element It) so that it presentsan upstanding flange having a face 15 on each side of the rectangularbody portion, which permits the connector to be readily mounted on thewall 31 of a housing. The mounting flange 14 is provided on the mountingface with a mounting flange seal 16, formed of a resilient compressiblesealing material, and in addition forms a bearing surface for contactbetween the top 11 and bottom 12 on securement or assembly of theconnector components. The opposing surfaces of the connector elements 11and 12 define, when the elements are secured together, a generallyrectangular transversely and laterally elongated opening 17, as seenmost clearly in FIGURE 4, which receives the insert portion 144 of theplug body 142.

A plurality of electrical spring contacts 22 extend longitudinallywithin the opening 17. Each electrical contact 22 is of a generallyC-shaped configuration having inwardly turned hook ends 23 and aprojecting ridge portion 24 midway between its ends. The electricalcontact 22 slopes outwardly or upwardly from its ridge portion 24 into acrest and then inwardly or downwardly to said hook ends. The crest islocated substantially nearer to the hook end, about one-third thedistance, relative to the ridge portion 24.

The electrical contacts 22 are arranged in a vertically staggeredrelationship within the opening 17 so that no two contacts are in thesame vertical plane. To retain the electrical contacts 22 from anysignificant movement along its length, a transverse notch 19 is recessedinto the top and bottom elements 11 and 12 which notch receives theridge portion 24 of the electrical contacts 22.

Each of the electrical contacts 22 are positioned substantially alongits length within a separate longitudinal slot 18 within the internalsurface of the rectangular opening 17. The slots 18 extend from theopening, as shown in FIGURE 4, to the adjacent surfaces of the top andbottom elements 11 and 12 so as to form a plurality of shoulders 21which the hook ends 23 of the electrical contacts 22 extend behind. Onlya short portion of each electrical contact 22 adjacent its crest extendsabove the longitudinal slot 18 so as to contact the electrical contacts146 and 147 of the plug 140.

The portion of the slot 18 which forms the shoulder 21 allows the hookend 23 of the electrical contact spring 22 to be depressed on insertionof the plug portion 144 into the opening 17 without deformation of thecontact element 22. This, together with the notch 19 and ridge portion24 relationship permits the ends 23 of the electrical contact 22 tofunction independently of one another. Thus, insertion of a plug member144 in one end of the connector will not cause the other half of theelectrical contact to rise or shift so as to cause overstressing andpermanent deformation when another plug (not shown) is inserted into theother end.

The electrical contacts 22 are spring loaded so as to urge itsoutersurface against the electrical contacts of a plug 140. They areprevented from rising or pivoting further than that shown about theridge portion 24 by their hook ends 23 which engage the shoulders 21.

An internal dust seal 26, formed of any suitable resilient material, ispositioned Within the notch 12, and is provided with cutouts 25 topermit passage of the contact spring 22 therethrough. Thus it is seenthat the spring contact element 22 is positioned at its mid-portionwithin the notch 19 by the spring foot 24, extending outwardly therefromeach end and having hooked ends 23 fitting around the hookshaped lug 20so that when they are snapped in place, the spring contact end 23 isretained by abutment with the shoulder 21 yet has limited verticalmovement. The connector 10 may be, in addition, provided with resilient,deformable external dust caps 27 having a plug receiving slot 28, thedust cap 27 being fitted around the ends 29 and 30 of the assembledconnector, only one of which caps is shown. The connector opening 17 isprovided with polarizing keyways 40 and 4-1, which keyways lie, as bestseen in FIGURE 5, in the same plane, so that they need be formed only onone element 11 or 12 of the connector 10. These keyways 4t and 41receive the keys and 156 of the plug element 144 (see FIGURE 1), thuspreventing insertion of the plug in any but the proper attitude,consequently obviating short circuits without requiring time to inspector determine polarity.

On one side of the connector element 10 is provided a retainer clip 50which is, as best seen in FIGURES 1 and 3, of a generally L-shapedconfiguration comprising a rectangular spring-like body 51 having ashort leg 52 extending at right angles thereto for engagement with theflat facing portion 32 of the extension or mounting flange 14, theextreme end of the retainer clip 50 angling outwardly as at 53 tofacilitate insertion of the plug member 142. Obviously, the leg 52 mayhave a pre-formed aperture 54 therein for reception of a mounting screw55 whenever desired. Extending inwardly from the top and bottom edges ofthe spring-like body 51 is a U-shaped spring retaining means 60 having adownwardly turned lip 61 at the end thereof, which lip is positioned ina rectangular slot or notch 62 (see FIGURE 1) formed in the surface ofthe connector elements 11 and 12. A shallow slot 63 may likewise beformed in these surfaces as an aid in positioning the spring clipretaining means 60.

While the retainer clip 50 has been described with reference to only oneside of the connector element 10, it is apparent that the other side, ifdesired, could be provided with the same retainer clip.

Referring now to FIGURES 6 and 7, it is seen that the spring contactelements 22 are provided with curved contact surfaces 42 so that theelectrical contact will always be in the center portion of the spring.This is advantageous in that it decreases or minimizes wear on the plugand contact spring, while at the same time it permits greater tolerancesin the manufacture of component parts, yet still obtains a goodelectrical contact surface. In addition, it should be noted that thecontact springs 22 have a relatively long length in comparison to theamount of deflection which is imparted on insertion of the plug 140,which relationship results in a more uniform contact pressure.

From the above specification, it will be seen that an improved connectorfor printed circuits and cables has been provided which overcomes mostof the difiiculties of the prior art, and in conjunction with theimproved plug attains results vastly superior to those of the knowndevices, and is of particular importance in miniaturized componenttechnology because of the stability and rug gedness of the connectionresulting therefrom. Obviously, many modifications and variations of thepresent invention are possible in light of the above teachings. It istherefore to be understood that within the scope of the appended claimsthe invention may be practiced other than as specifically described.

What is claimed is:

1. An electrical double ended socket, comprising:

(a) a housing having an opening extending therethrough;

(b) a plurality of elongated electrical contacts extendinglongitudinally within said opening;

(0) each said electrical contact having inwardly turned hook ends and aprojecting ridge portion midway between its ends;

(d) each said electrical contact sloping outwardly from said ridgeportion into a crest and then inwardly to said hook ends, said crestlocated relatively nearer the hook ends than the ridge portion;

(e) each said electrical contact having its transverse surface outwardlycurved;

(f) said internal surface defining said opening having a transversenotch substantially midway of said opening which receives the ridgeportion of said electrical contacts;

(g) each said electrical contact being positioned substantially alongits length within a separate longitudinal slot within the internalsurface defining said opening;

(h) said longitudinal slots extending from the opening to the adjacentsurfaces of the housing so as to form a plurality of shoulders which thehook ends of the electrical contacts extend behind; and

(i) a portion of each said electrical contact adjacent its crestextending above its longitudinal slot within the internal surface so asto contact the electric contacts of a plug adapted to be inserted withsaid opening.

2. An electrical double ended socket, comprising:

(a) a housing having a rectangular opening extending therethrough;

(b) a plurality of elongated electrical contacts extendinglongitudinally within said opening;

(0) each said electrical contact having inwardly turned hook ends and aprojecting ridge portion midway between its ends;

(d) each said electrical contact sloping outwardly from said ridgeportion into a crest and then inwardly to said hook ends, said crestlocated substantially nearer said hook ends relative to the ridgeportion;

(e) said electrical contacts being arranged in a vertically staggeredrelationship within said opening so that one electrical contact ispositioned along one longitudinal surface formed by said rectangularopening and the other electrical contact is positioned along the opposedlongitudinal surface formed by said rectangular opening;

(1) said one longitudinal surface having a transverse notchsubstantially midway of said opening which receives the ridge portionsof said electrical contacts along that surface, and said otherlongitudinal surface having a corresponding notch which receives theridge portion of said electrical contacts along that surface whereby thecrest portions of each said electrical contacts will functionsubstantially independent of each other and to prevent any appreciablemovement of the electrical contact along the direction of its lengthwith respect to the housing;

(g) each said electrical contact being positioned substantially alongits length within a separate longitudinal slot within the internalsurface formed by said rectangular opening;

(h) said longitudinal slots extending from the opening to the adjacentsurfaces of the housing so as to form a plurality of shoulders which thehook ends of the electrical contacts extend behind; and

(i) a portion of each said electrical contact adjacent its crestextending above its longitudinal slot within the internal surface so asto contact the electrical contacts of a plug adapted to be insertedwithin said opening.

References Cited in the file of this patent UNITED STATES PATENTS1,569,869 McIntosh Jan. 19, 1926 2,175,245 Brockman Oct. 10, 19392,265,341 Borchert Dec. 9, 1941 2,296,454 Schauer Sept. 22, 19422,383,926 White Aug. 28, 1945 2,440,279 Larkins Apr. 27, 1948 2,619,515Doane Nov. 25, 1952 2,699,534 Klostermann Ian. 11, 1955 2,760,174 Burttet a1 Aug. 21, 1956 2,765,450 Richardson Oct. 2, 1956 2,802,188 BaddersAug. 6, 1957 2,875,425 Gilbert Feb. 24, 1959 2,925,537 Winkler Feb. 16,1960 3,090,028 Hall et al. May 14, 1963

1. AN ELECTRICAL DOUBLE ENDED SOCKET, COMPRISING: (A) A HOUSING HAVINGAN OPENING EXTENDING THERETHROUGH; (B) A PLURALITY OF ELONGATEDELECTRICAL CONTACTS EXTENDING LONGITUDINALLY WITHIN SAID OPENING; (C)EACH SAID ELECTRICAL CONTACT HAVING INWARDLY TURNED HOOK ENDS AND APROJECTING RIDGE PORTION MIDWAY BETWEEN ITS ENDS; (D) EACH SAIDELECTRICAL CONTACT SLOPING OUTWARDLY FROM SAID RIDGE PORTION INTO ACREST AND THEN INWARDLY TO SAID HOOK ENDS, SAID CREST LOCATED RELATIVELYNEARER THE HOOK ENDS THAN THE RIDGE PORTION; (E) EACH SAID ELECTRICALCONTACT HAVING ITS TRANSVERSE SURFACE OUTWARDLY CURVED; (F) SAIDINTERNAL SURFACE DEFINING SAID OPENING HAVING A TRANSVERSE NOTCHSUBSTANTIALLY MIDWAY OF SAID OPENING WHICH RECEIVES THE RIDGE PORTION OFSAID ELECTRICAL CONTACTS; (G) EACH SAID ELECTRICAL CONTACT BEINGPOSITIONED SUBSTANTIALLY ALONG ITS LENGTH WITHIN A SEPARATE LONGITUDINALSLOT WITHIN THE INTERNAL SURFACE DEFINING SAID OPENING; (H) SAIDLONGITUDINAL SLOTS EXTENDING FROM THE OPENING TO THE ADJACENT SURFACESOF THE HOUSING SO AS TO FORM A PLURALITY OF SHOULDERS WHICH THE HOOKENDS OF THE ELECTRICAL CONTACTS EXTEND BEHIND; AND (I) A PORTION OF EACHSAID ELECTRICAL CONTACT ADJACENT ITS CREST EXTENDING ABOVE ITSLONGITUDINAL SLOT WITHIN THE INTERNAL SURFACE SO AS TO CONTACT THEELECTRIC CONTACTS OF A PLUG ADAPTED TO BE INSERTED WITH SAID OPENING.